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1.
Mol Ther ; 32(6): 1934-1955, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38582961

RESUMO

Second mitochondrial-derived activator of caspase (SMAC), also known as direct inhibitor of apoptosis-binding proteins with low pI (Diablo), is known as a pro-apoptotic mitochondrial protein released into the cytosol in response to apoptotic signals. We recently reported SMAC overexpression in cancers as essential for cell proliferation and tumor growth due to non-apoptotic functions, including phospholipid synthesis regulation. These functions may be associated with its interactions with partner proteins. Using a peptide array with 768 peptides derived from 11 selected SMAC-interacting proteins, we identified SMAC-interacting sequences. These SMAC-binding sequences were produced as cell-penetrating peptides targeted to the cytosol, mitochondria, or nucleus, inhibiting cell proliferation and inducing apoptosis in several cell lines. For in vivo study, a survivin/baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5)-derived peptide was selected, due to its overexpression in many cancers and its involvement in mitosis, apoptosis, autophagy, cell proliferation, inflammation, and immune responses, as a target for cancer therapy. Specifically, a SMAC-targeting survivin/BIRC5-derived peptide, given intratumorally or intravenously, strongly inhibited lung tumor growth, cell proliferation, angiogenesis, and inflammation, induced apoptosis, and remodeled the tumor microenvironment. The peptide promoted tumor infiltration of CD-8+ cells and increased cell-intrinsic programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1) expression, resulting in cancer cell self-destruction and increased tumor cell death, preserving immune cells. Thus, targeting the interaction between the multifunctional proteins SMAC and survivin represents an innovative therapeutic cancer paradigm.


Assuntos
Proteínas Reguladoras de Apoptose , Apoptose , Proliferação de Células , Proteínas Mitocondriais , Survivina , Humanos , Survivina/metabolismo , Survivina/genética , Animais , Camundongos , Proteínas Mitocondriais/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/tratamento farmacológico , Inflamação/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Ligação Proteica , Proteínas Inibidoras de Apoptose/metabolismo , Proteínas Inibidoras de Apoptose/genética , Peptídeos Penetradores de Células/farmacologia , Peptídeos Penetradores de Células/química , Peptídeos/farmacologia , Peptídeos/química , Terapia de Imunossupressão
2.
Mol Microbiol ; 120(6): 845-873, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37818865

RESUMO

Thermostable direct haemolysin (TDH) is the key virulence factor secreted by the human gastroenteric bacterial pathogen Vibrio parahaemolyticus. TDH is a membrane-damaging pore-forming toxin. It evokes potent cytotoxicity, the mechanism of which still remains under-explored. Here, we have elucidated the mechanistic details of cell death response elicited by TDH. Employing Caco-2 intestinal epithelial cells and THP-1 monocytic cells, we show that TDH induces some of the hallmark features of apoptosis-like programmed cell death. TDH triggers caspase-3 and 7 activations in the THP-1 cells, while caspase-7 activation is observed in the Caco-2 cells. Interestingly, TDH appears to induce caspase-independent cell death. Higher XIAP level and lower Smac/Diablo level upon TDH intoxication provide plausible explanation for the functional inability of caspases in the THP-1 cells, in particular. Further exploration reveals that mitochondria play a central role in the TDH-induced cell death. TDH triggers mitochondrial damage, resulting in the release of AIF and endonuclease G, responsible for the execution of caspase-independent cell death. Among the other critical mediators of cell death, ROS is found to play an important role in the THP-1 cells, while PARP-1 appears to play a critical role in the Caco-2 cells. Altogether, our work provides critical new insights into the mechanism of cell death induction by TDH, showing a common central theme of non-classical programmed cell death. Our study also unravels the interplay of crucial molecules in the underlying signalling processes. Our findings add valuable insights into the role of TDH in the context of the host-pathogen interaction processes.


Assuntos
Vibrio parahaemolyticus , Humanos , Células CACO-2 , Apoptose , Caspases
3.
Int J Mol Sci ; 25(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38612670

RESUMO

We aimed to identify serum exosomal microRNAs (miRNAs) associated with the transition from atrial fibrillation (AF) to sinus rhythm (SR) and investigate their potential as biomarkers for the early recurrence of AF within three months post-treatment. We collected blood samples from eight AF patients at Chang Gung Memorial Hospital in Taiwan both immediately before and within 14 days following rhythm control treatment. Exosomes were isolated from these samples, and small RNA sequencing was performed. Using DESeq2 analysis, we identified nine miRNAs (16-2-3p, 22-3p, 23a-3p, 23b-3p, 125a-5p, 328-3p, 423-5p, 504-5p, and 582-3p) associated with restoration to SR. Further analysis using the DIABLO model revealed a correlation between the decreased expression of miR-125a-5p and miR-328-3p and the early recurrence of AF. Furthermore, early recurrence is associated with a longer duration of AF, presumably indicating a more extensive state of underlying cardiac remodeling. In addition, the reads were mapped to mRNA sequences, leading to the identification of 14 mRNAs (AC005041.1, ARHGEF12, AMT, ANO8, BCL11A, DIO3OS, EIF4ENIF1, G2E3-AS1, HERC3, LARS, NT5E, PITX1, SLC16A12, and ZBTB21) associated with restoration to SR. Monitoring these serum exosomal miRNA and mRNA expression patterns may be beneficial for optimizing treatment outcomes in AF patients.


Assuntos
Fibrilação Atrial , Exossomos , MicroRNAs , Humanos , Fibrilação Atrial/genética , MicroRNAs/genética , Coração , Exossomos/genética , RNA Mensageiro , Anoctaminas
4.
Apoptosis ; 28(5-6): 730-753, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37014578

RESUMO

Apoptosis is a process of programmed cell death in which a cell commits suicide while maintaining the integrity and architecture of the tissue as a whole. Apoptosis involves activation of one of two major pathways: the extrinsic pathway, where extracellular pro-apoptotic signals, transduced through plasma membrane death receptors, activate a caspase cascade leading to apoptosis. The second, the intrinsic apoptotic pathway, where damaged DNA, oxidative stress, or chemicals, induce the release of pro-apoptotic proteins from the mitochondria, leading to the activation of caspase-dependent and independent apoptosis. However, it has recently become apparent that proteins involved in apoptosis also exhibit non-cell death-related physiological functions that are related to the cell cycle, differentiation, metabolism, inflammation or immunity. Such non-conventional activities were predominantly reported in non-cancer cells although, recently, such a dual function for pro-apoptotic proteins has also been reported in cancers where they are overexpressed. Interestingly, some apoptotic proteins translocate to the nucleus in order to perform a non-apoptotic function. In this review, we summarize the unconventional roles of the apoptotic proteins from a functional perspective, while focusing on two mitochondrial proteins: VDAC1 and SMAC/Diablo. Despite having pro-apoptotic functions, these proteins are overexpressed in cancers and this apparent paradox and the associated pathophysiological implications will be discussed. We will also present possible mechanisms underlying the switch from apoptotic to non-apoptotic activities although a deeper investigation into the process awaits further study.


Assuntos
Apoptose , Neoplasias , Humanos , Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Caspases/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo
5.
J Biol Chem ; 296: 100383, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33556373

RESUMO

The rhomboid protease PARL is a critical regulator of mitochondrial homeostasis through its cleavage of substrates such as PINK1, PGAM5, and Smac/Diablo, which have crucial roles in mitochondrial quality control and apoptosis. However, the catalytic properties of PARL, including the effect of lipids on the protease, have never been characterized in vitro. To address this, we isolated human PARL expressed in yeast and used FRET-based kinetic assays to measure proteolytic activity in vitro. We show that PARL activity in detergent is enhanced by cardiolipin, a lipid enriched in the mitochondrial inner membrane. Significantly higher turnover rates were observed for PARL reconstituted in proteoliposomes, with Smac/Diablo being cleaved most rapidly at a rate of 1 min-1. In contrast, PGAM5 is cleaved with the highest efficiency (kcat/KM) compared with PINK1 and Smac/Diablo. In proteoliposomes, a truncated ß-cleavage form of PARL, a physiological form known to affect mitochondrial fragmentation, is more active than the full-length enzyme for hydrolysis of PINK1, PGAM5, and Smac/Diablo. Multiplex profiling of 228 peptides reveals that PARL prefers substrates with a bulky side chain such as Phe in P1, which is distinct from the preference for small side chain residues typically found with bacterial rhomboid proteases. This study using recombinant PARL provides fundamental insights into its catalytic activity and substrate preferences that enhance our understanding of its role in mitochondrial function and has implications for specific inhibitor design.


Assuntos
Metaloproteases/metabolismo , Metaloproteases/fisiologia , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/fisiologia , Proteínas Reguladoras de Apoptose/metabolismo , Domínio Catalítico , Endopeptidases/metabolismo , Células HEK293 , Células HeLa , Humanos , Metaloproteases/genética , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Peptídeo Hidrolases/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteólise
6.
Biochem Biophys Res Commun ; 568: 180-185, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34247143

RESUMO

XIAP is multi-functional protein which regulates apoptosis acting as a direct caspase inhibitor. It is overexpressed in cancer cells, where it antagonizes the pro-apoptotic action of chemotherapeutics, and therefore it has become an important target for the treatment of cancer. In cells undergoing programmed cell death, the pro-apoptotic protein Smac is released by the mitochondria and binds to XIAP, thereby blocking caspase inhibition. Thus, Smac is considered a master regulator of apoptosis in mammals. In this regard, several Smac mimetic compounds have been developed to inhibit XIAP activity in cancer tissues. These compounds have shown low efficacy, partly due to the lack of structural knowledge of the XIAP-Smac interaction. In this work, through SEC-MALS and circular dichroism, we provide the first biophysical characterization of the interaction between the full-length form of XIAP and Smac, determining the stoichiometry of the complex and providing important information to develop more effective XIAP inhibitors.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Proteínas Reguladoras de Apoptose/química , Humanos , Proteínas Mitocondriais/química , Neoplasias/metabolismo , Ligação Proteica , Mapas de Interação de Proteínas , Multimerização Proteica , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/química
7.
Int J Mol Sci ; 21(3)2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31973107

RESUMO

Thyroid carcinoma is the most common endocrine cancer and includes different forms. Among these, anaplastic thyroid carcinoma (ATC) is the rarest but the most lethal subtype, compared to papillary thyroid carcinoma (PTC) which shows an overall good prognosis. We have previously showed that Tumor Suppressor Candidate 2 (TUSC2), a known tumour suppressor gene, is downregulated in human PTC and ATC compared to normal thyroid samples. The aim of this study was to gain insight into the molecular mechanisms induced by TUSC2 in thyroid cancer cells. Here, we stably transfected TUSC2 in papillary (TPC-1) and in anaplastic (8505C) thyroid cancer cell lines and studied its effects on several biological processes, demonstrating that TUSC2 overexpression decreased thyroid cancer cell proliferation, migration and invasion. Through the proteome profiler apoptosis array, we observed that TUSC2 increased sensitivity to apoptosis by increasing the SMAC/DIABLO and CYTOCHROME C proteins. On the other hand, transient silencing of TUSC2, by siRNA, in an immortalized thyroid follicular epithelial cell line (Nthy-ori 3-1) showed the opposite effect. Finally modulation of SMAC/DIABLO partially rescued the biological effects of TUSC2. Thus, our data highlight a tumour suppressor role of TUSC2 in thyroid carcinogenesis, suggesting that it could be a promising target and biomarker for thyroid carcinoma.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Mitocondriais/metabolismo , Fenótipo , Neoplasias da Glândula Tireoide/metabolismo , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteínas Supressoras de Tumor/metabolismo , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Genes Supressores de Tumor , Humanos , RNA Interferente Pequeno , Câncer Papilífero da Tireoide , Carcinoma Anaplásico da Tireoide , Neoplasias da Glândula Tireoide/patologia , Proteínas Supressoras de Tumor/genética
8.
J Infect Dis ; 219(6): 975-985, 2019 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-30597040

RESUMO

Drug-resistant tuberculosis represents a global emergency, requiring new drugs. We found that minocycline was highly potent in laboratory strains of Mycobacterium tuberculosis and that 30 drug-susceptible and multidrug/extensively drug-resistant clinical strains were susceptible to clinically achievable concentrations. In the hollow fiber system model, lung concentration-time profiles of 7 mg/kg/day human-equivalent minocycline dose achieved bacterial kill rates equivalent to those of first-line antituberculosis agents. Minocycline killed extracellular bacilli directly. Minocycline also killed intracellular bacilli indirectly, via concentration-dependent granzyme A-driven apoptosis. Moreover, minocycline demonstrated dose-dependent antiinflammatory activity and downregulation of extracellular matrix-based remodeling pathways and, thus, could protect patients from tuberculosis immunopathology. In RNA sequencing of repetitive samples from the hollow fiber system and in independent protein abundance experiments, minocycline demonstrated dose-dependent inhibition of sonic hedgehog-patched-gli signaling. These findings have implications for improved lung remodeling and for dual immunomodulation and direct microbial kill-based treatment shortening regimens for drug-susceptible and drug-resistant latent and active M. tuberculosis infection.


Assuntos
Antituberculosos/farmacologia , Minociclina/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Granzimas/metabolismo , Proteínas Hedgehog , Humanos , Testes de Sensibilidade Microbiana , Transdução de Sinais , Células THP-1 , Tuberculose/imunologia , Tuberculose/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/imunologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
9.
Fish Shellfish Immunol ; 84: 587-598, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30336283

RESUMO

The mitochondrial pathway of apoptosis is well studied as the major mechanism of physiological cell death in vertebrates. In the present study, a second mitochondria-derived activator of caspases (Smac)/direct inhibitor of apoptosis-binding protein (IAP) with low pI protein (DIABLO) (designated as CgSmac) was identified from oyster Crassostrea gigas. The open reading frame of CgSmac was of 966 bp nucleotides encoding a predicted polypeptide of 321 amino acids with a conserved Smac/DIABLO domain containing a potential IAP-binding motif of VMPV. CgSmac proteins were distributed in hemocytes and co-localized with mitochondria. Western blotting analysis revealed that CgSmac proteins mainly existed in the dimer form in hemocytes, and the monomeric precursors and mature monomers were also detected. After lipopolysaccharide (LPS) stimulation, the mRNA expression of CgSmac in hemocytes was significantly up-regulated and peaked at 6 h (12.26-fold, p < 0.05), and the protein level of its dimers was significantly up-regulated at 6 h, 12 h, 24 h, and 48 h, while that of CgSmac monomers was up-regulated at 6 h, 12 h and down-regulated at 24 h, 48 h. The decrease of mitochondrial membrane potential indicated that the occurrence of early stage of apoptosis in primary cultured hemocytes was induced by LPS, and RNA interference (RNAi) of CgSmac could not rescue this decrease. The caspase-3 activity in primary cultured hemocytes was significantly suppressed after RNAi of CgSmac. Correspondingly, the total apoptotic rate of primary cultured hemocytes was also significantly suppressed in dsCgSmac + LPS group (31.57%) compared to dsEGFP + LPS group (40.27%, p < 0.05), which in turn demonstrated the conserved pro-apoptotic function of CgSmac. Furthermore, the early apoptotic rate (10.4% vs. 8.5%, p < 0.05) was significantly higher in dsCgSmac + LPS group than that of dsEGFP + LPS group, while the necrosis (7.7% vs. 10.0%, p < 0.05) and late apoptotic rates (13.4% vs. 21.9%, p < 0.05) were lower in dsCgSmac + LPS group than those of dsEGFP + LPS group. Collectively, CgSmac could activate mitochondrial apoptosis pathway by promoting caspase-3 activity in oyster hemocytes against exogenous LPS invasion. These results provided new insights on oyster apoptosis and the immune defense mechanisms in invertebrates.


Assuntos
Apoptose/efeitos dos fármacos , Crassostrea/genética , Crassostrea/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Mitocôndrias/fisiologia , Sequência de Aminoácidos , Animais , Apoptose/genética , Sequência de Bases , Peptídeos e Proteínas de Sinalização Intracelular/química , Lipopolissacarídeos/farmacologia , Proteínas Mitocondriais/química , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/imunologia , Alinhamento de Sequência
10.
Mol Ther ; 26(3): 680-694, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29396267

RESUMO

The mitochondrial pro-apoptotic protein SMAC/Diablo participates in apoptosis by negatively regulating IAPs and activating caspases, thus encouraging apoptosis. Unexpectedly, we found that SMAC/Diablo is overexpressed in cancer. This paradox was addressed here by silencing SMAC/Diablo expression using specific siRNA (si-hSMAC). In cancer cell lines and subcutaneous lung cancer xenografts in mice, such silencing reduced cell and tumor growth. Immunohistochemistry and electron microscopy of the si-hSMAC-treated residual tumor demonstrated morphological changes, including cell differentiation and reorganization into glandular/alveoli-like structures and elimination of lamellar bodies, surfactant-producing organs. Next-generation sequencing of non-targeted or si-hSMAC-treated tumors revealed altered expression of genes associated with the cellular membrane and extracellular matrix, of genes found in the ER and Golgi lumen and in exosomal networks, of genes involved in lipid metabolism, and of lipid, metabolite, and ion transporters. SMAC/Diablo silencing decreased the levels of phospholipids, including phosphatidylcholine. These findings suggest that SMAC/Diablo possesses additional non-apoptotic functions related to regulating lipid synthesis essential for cancer growth and development and that this may explain SMAC/Diablo overexpression in cancer. The new lipid synthesis-related function of the pro-apoptotic protein SMAC/Diablo in cancer cells makes SMAC/Diablo a promising therapeutic target.


Assuntos
Transformação Celular Neoplásica/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Fosfolipídeos/biossíntese , Animais , Apoptose , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/genética , Modelos Animais de Doenças , Expressão Gênica , Inativação Gênica , Xenoenxertos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Modelos Biológicos , Neoplasias/etiologia , Neoplasias/metabolismo , Neoplasias/patologia , Transporte Proteico , RNA Interferente Pequeno/genética
11.
Amino Acids ; 50(11): 1607-1616, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30123940

RESUMO

The second mitochondria-derived activator of caspase (Smac/DIABLO) is a pro-apoptotic protein that released from mitochondria into the cytosol when cells undergo apoptosis. Smac promotes caspase activation by binding the inhibitors of apoptosis proteins (IAP), particularly XIAP and eliminating their inhibitory activity. Although the seven N-terminal amino acids AVPIAQK (SmacN7) of Smac protein is able to elicit an anticancer response by itself, it is neither cell-permeable nor stable in the cellular environment. Thus, the use of SmacN7 derivatives and mimetics is an alluring field for cancer therapy. In this study, heptamer Smac peptide was fused to a well-known octaarginine cell-penetrating peptide for promoting its intracellular access. Both therapeutic Smac part and cell-penetrating octaarginine parts of the peptide sequence constrained in a cyclic structure so as to enhance the apoptosis-inducing potential of the SmacN7 peptide. Biological assays interestingly showed that cyclic peptides P4, P5 and P7 gave rise to a significant level of cytotoxicity and apoptosis mediated cell death in multiple myeloma tumor cells (MM) comparing to linear peptide.


Assuntos
Antineoplásicos , Apoptose/efeitos dos fármacos , Peptídeos Penetradores de Células , Mieloma Múltiplo/tratamento farmacológico , Oligopeptídeos , Peptídeos , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/síntese química , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacologia , Humanos , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Oligopeptídeos/síntese química , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Peptídeos/síntese química , Peptídeos/química , Peptídeos/farmacologia , Relação Estrutura-Atividade
12.
J Asian Nat Prod Res ; 20(9): 897-908, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29304559

RESUMO

A series of asiatic acid derivatives were synthesized and their cytotoxicities in vitro against two cancer cell lines (HepG2 and SGC7901) were evaluated by MTT assay. The results showed that compounds I2, I6, and II6 have more potent anticancer activity than that of the positive control drug paclitaxel. The interactions between the compounds I2, I6, and II6 and survivin were also studied by docking simulations.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Triterpenos Pentacíclicos/química , Survivina/antagonistas & inibidores , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Modelos Moleculares , Estrutura Molecular , Paclitaxel/farmacologia
13.
Toxicol Appl Pharmacol ; 297: 12-21, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26933830

RESUMO

The popularity of hair dyes use has been increasing regularly throughout the world as per the demand of hair coloring fashion trends and other cosmetic products. 2-Amino-3-hydroxypyridine (A132) is widely used as a hair dye ingredient around the world. We are reporting first time the phototoxicity mechanism of A132 under ambient environmental UV-B radiation. It showed maximum absorption in UV-B region (317 nm) and forms a photoproduct within an hour exposure of UV-B irradiation. Photocytotoxicity of A132 in human keratinocytes (HaCaT) was measured by mitochondrial (MTT), lysosomal (NRU) and LDH assays which illustrated the significant reduction in cell viability. The role of reactive oxygen species (ROS) generation for A132 phototoxicity was established photo- chemically as well as intracellularly. Noteworthy, formation of tail DNA (comet assay), micronuclei and cyclobutane pyrimidine dimers (CPDs) (immunocytochemistry) formation confirmed the photogenotoxic potential of dye. Cell cycle study (sub-G1peak) and staining with EB/AO revealed the cell cycle arrest and apoptosis. Further, mitochondrial mediated apoptosis was corroborated by reduced MMP, release of cytochrome c and upregulation of caspase-3. Release of mitochondrial Smac/DIABLO in cytoplasm demonstrated the caspase dependent apoptotic cell death by photolabile A132 dye. In-addition increased Bax/Bcl2 ratio again proved the apoptosis. Thus, study suggests that A132 induces photogenotoxicity, phototoxicity and apoptotic cell death through the involvement of Smac/DIABLO in mitochondrial apoptosis via caspase dependent manner. Therefore, the long term use of A132 dye and sunlight exposure jointly increased the oxidative stress in skin which causes premature hair loss, damage to progenitor cells of hair follicles.


Assuntos
Aminopiridinas , Tinturas para Cabelo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Queratinócitos/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Mutagênicos , Raios Ultravioleta , Aminopiridinas/efeitos da radiação , Aminopiridinas/toxicidade , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Dano ao DNA , Tinturas para Cabelo/efeitos da radiação , Tinturas para Cabelo/toxicidade , Humanos , Queratinócitos/metabolismo , Queratinócitos/fisiologia , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Mutagênicos/efeitos da radiação , Mutagênicos/toxicidade , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Proteína X Associada a bcl-2/metabolismo
14.
Tumour Biol ; 37(5): 6837-45, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26662313

RESUMO

MicroRNA-27a (miR-27a) has been reported to be an onco-microRNA in multiple cancers promoting tumor growth and metastasis, but the role of miR-27a in regulating the cancer sensitivity to chemotherapy remains unknown. In this study, upregulation of miR-27a was validated by real-time PCR analysis in breast cancer (BC) cell lines and samples of BC patients. A negative correlation between miR-27a and bak was also observed in normal breast epithelial cell line MCF-10A and BC cell lines, suggesting that the bak is the potential target of miR-27a. miR-27a could modulate the growth and metastasis of BC cells. More importantly, we found that knockdown of miR-27a by the specific inhibitors significantly increased the sensitivity of T-47D cells to cisplatin (CDDP) treatment. After further investigation, we indicated that the knockdown of miR-27a promoted the apoptosis via mitochondrial pathway in T-47D cells treated with CDDP, depending on the BAK-second mitochondria-derived activator of caspase/direct IAP binding protein with low pI (SMAC/DIABLO)-X-linked inhibitor of apoptosis (XIAP) axis. Interestingly, we found that the sensitivity of T-47D cells to some other chemotherapeutic agents (5-fluorouracil, doxorubicin, and tumor necrosis factor-related apoptosis-inducing ligand) was also regulated by miR-27a. These findings improve our understanding of the role of miR-27a in breast cancer and might provide a novel strategy for cancer therapy.


Assuntos
Neoplasias da Mama/genética , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , MicroRNAs/genética , Proteínas Mitocondriais/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Regiões 3' não Traduzidas , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose , Sequência de Bases , Sítios de Ligação , Neoplasias da Mama/metabolismo , Estudos de Casos e Controles , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Mitocondriais/metabolismo , Interferência de RNA , Transdução de Sinais , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo
15.
Adv Exp Med Biol ; 867: 293-316, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26530373

RESUMO

The treatment of metastasized bladder cancer has been evolving during recent years. Cisplatin based chemotherapy combinations are still gold standard in the treatment of advanced and metastasized bladder cancer. But new therapies are approaching. Based to this fact biological markers will become more important for decisions in bladder cancer treatment. A systematic MEDLINE search of the key words "cisplatin", "bladder cancer", "DNA marker", "protein marker", "methylation biomarker", "predictive marker", "prognostic marker" has been made. This review aims to highlight the most relevant clinical and experimental studies investigating markers for metastasized transitional carcinoma of the urothelium treated by cisplatin based regimens.


Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/análise , Cisplatino/uso terapêutico , Neoplasias da Bexiga Urinária/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP/análise , Basigina/análise , Proteínas de Ligação a DNA/análise , Endonucleases/análise , Humanos , Proteínas Inibidoras de Apoptose/análise , Receptor ErbB-2/análise , Survivina , Neoplasias da Bexiga Urinária/diagnóstico
16.
Conserv Biol ; 28(3): 783-9, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24405332

RESUMO

Understanding the risk of a local extinction in a single population relative to the habitat requirements of a species is important in both theoretical and applied ecology. Local extinction risk depends on several factors, such as habitat requirements, range size of species, and habitat quality. We studied the local extinctions among 31 dragonfly and damselfly species from 1930 to 1975 and from 1995 to 2003 in Central Finland. We tested whether habitat specialists had a higher local extinction rate than generalist species. Approximately 30% of the local dragonfly and damselfly populations were extirpated during the 2 study periods. The size of the geographical range of the species was negatively related to extinction rate of the local populations. In contrast to our prediction, the specialist species had lower local extinction rates than the generalist species, probably because generalist species occurred in both low- and high-quality habitat. Our results are consistent with source-sink theory.


Assuntos
Ecossistema , Extinção Biológica , Odonatos/fisiologia , Conservação dos Recursos Naturais , Finlândia , Água Doce , Geografia , Medição de Risco , Estações do Ano
17.
J Anal Psychol ; 69(2): 195-206, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38482982

RESUMO

Given the unprecedented events unfolding around the globe over the past four years, psychoanalytic communities near and far have sought to ask and ventured to answer the question: What does psychoanalysis have to offer individuals, and the collective, as a way of seeing and being with the reality of what is? Taking up these questions in such a time as this, feels, perhaps inevitably, unsafe. Sometimes it can feel as if there is a silent and unspoken mandate to ensure safety at all costs when we seek to find a spirit of the depth's response to the spirit of the times. I propose that the work of psychoanalysis is grounded in nothing but the journey through that which is unsafe. This article will take up Ann Ulanov's notion that one's own evil is the hinge door into collective and archetypal evil. To become unhinged means to risk well-formulated understandings, theories, and modalities about being and becoming for the other and instead to allow the other to penetrate that which is unknown in ourselves, upending our well-formed theories and pressing us to take up our own lives in new and unpredictable ways.


Compte tenu des événements sans précédent qui se sont déroulés dans le monde entier au cours des quatre dernières années, les communautés psychanalytiques proches et lointaines ont cherché à poser la question suivante et à y proposer des réponses: qu'est­ce que la psychanalyse peut offrir aux individus, et au collectif, comme moyen de voir et d'être avec la réalité de ce qui est ? Aborder ces questions dans un moment comme celui­ci nous fait nous sentir en danger, et c'est peut­être inévitable. Parfois, on peut avoir le sentiment qu'il y a un décret silencieux et tacite d'assurer la sécurité à tout prix lorsque nous cherchons à trouver une réponse de l'esprit des profondeurs à l'esprit du temps. Je propose que le travail de la psychanalyse n'est fondé sur rien d'autre que le voyage à travers ce qui est dangereux, risqué. C'est, en effet, ce qu'implique la recherche d'une conversation active et vivante avec l'esprit des profondeurs et c'est ce qui distingue le travail de thérapie du travail de psychanalyse. Si nous nous enfermons dans des notions de sécurité, nous resterons liés à des notions similaires d'anonymat analytique et d'innocence, restant inconscients de notre propre implication dans les horreurs qui continuent d'aliéner, d'étouffer et d'isoler ceux qui sont en marge. Cette présentation reprendra la conception d'Ann Ulanov selon laquelle le mal d'une personne est la porte charnière du mal collectif et archétypal. Notre travail, individuellement et collectivement, est de descendre dans ce territoire dangereux à l'intérieur de nous­mêmes pour voir ce qui s'y est passé et ce qui reste à vivre dans les zones d'ombre. Devenir déséquilibré signifie mettre en doute des compréhensions, des théories et des modalités bien formulées sur l'être et le devenir pour l'autre et, à la place, permettre à l'autre de pénétrer ce qui est inconnu en nous­mêmes, bouleversant nos théories bien formées et nous poussant à prendre notre propre vie en main d'une manière nouvelle et imprévisible. En ce sens, la psychanalyse est intrinsèquement une forme d'activisme intérieur et extérieur. Ce qui est proposé ici est un regard sur la façon dont la psychanalyse, déséquilibrée, se déplace au­delà des murs sécurisants et au­delà des murs de la salle de consultation vers le monde au sens large.


Dados los acontecimientos sin precedentes que han tenido lugar en todo el mundo en los últimos cuatro años, las comunidades psicoanalíticas cercanas y lejanas han tratado de preguntarse y han intentado responder a la pregunta: ¿qué tiene el psicoanálisis que ofrecer a los individuos, y al colectivo, en términos de ver y estar con la realidad de lo que acontece? Abordar estas cuestiones en un momento como el actual puede resultar inevitablemente inseguro. A veces puede dar la sensación de que existe un mandato silencioso y tácito de garantizar la seguridad a toda costa cuando tratamos de encontrar una respuesta del espíritu de las profundidades al espíritu de los tiempos. Propongo que el trabajo del psicoanálisis no se basa en otra cosa que en el viaje a través de lo que es inseguro. Esto, de hecho, es lo que implica buscar una conversación activa y viva con el espíritu de las profundidades y es lo que distingue el trabajo de la terapia del trabajo del psicoanálisis. Si nos encerráramos en las nociones de seguridad, seguiríamos limitados por nociones similares de neutralidad analítica e inocencia, permaneciendo inconscientes de nuestra propia implicancia en los horrores que continúan ajenos, encerrando y aislando a aquellos que se encuentran en los márgenes. Esta presentación retomará la noción de Ann Ulanov de que el mal propio es la puerta de entrada al mal colectivo y arquetipal. Nuestro trabajo individual y colectivo es descender a este territorio inseguro dentro de nosotros mismos para ver lo que ocurrió allí y lo que permanece viviendo en las sombras. Perturbarse significa arriesgar comprensiones, teorías y modalidades bien formuladas sobre el ser y el devenir para el otro y, en su lugar, permitir que el otro penetre en lo que es desconocido en nosotros mismos, trastornando nuestras teorías bien formadas y presionándonos para que asumamos nuestras propias vidas de maneras nuevas e impredecibles. De este modo, el psicoanálisis es inherentemente una forma de activismo interior y exterior. Lo que se ofrece es una mirada sobre cómo el psicoanálisis, perturbado, traspasa los muros de la seguridad y va más allá de las paredes del consultorio analítico para adentrarse en el mundo en general.


Assuntos
Emoções , Psicanálise , Humanos , Estudos Prospectivos
18.
J Hepatol ; 59(3): 583-94, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23567086

RESUMO

Inflammation can be either beneficial or detrimental to the liver, depending on multiple factors. Mild (i.e., limited in intensity and destined to resolve) inflammatory responses have indeed been shown to exert consistent hepatoprotective effects, contributing to tissue repair and promoting the re-establishment of homeostasis. Conversely, excessive (i.e., disproportionate in intensity and permanent) inflammation may induce a massive loss of hepatocytes and hence exacerbate the severity of various hepatic conditions, including ischemia-reperfusion injury, systemic metabolic alterations (e.g., obesity, diabetes, non-alcoholic fatty liver disorders), alcoholic hepatitis, intoxication by xenobiotics and infection, de facto being associated with irreversible liver damage, fibrosis, and carcinogenesis. Both liver-resident cells (e.g., Kupffer cells, hepatic stellate cells, sinusoidal endothelial cells) and cells that are recruited in response to injury (e.g., monocytes, macrophages, dendritic cells, natural killer cells) emit pro-inflammatory signals including - but not limited to - cytokines, chemokines, lipid messengers, and reactive oxygen species that contribute to the apoptotic or necrotic demise of hepatocytes. In turn, dying hepatocytes release damage-associated molecular patterns that-upon binding to evolutionary conserved pattern recognition receptors-activate cells of the innate immune system to further stimulate inflammatory responses, hence establishing a highly hepatotoxic feedforward cycle of inflammation and cell death. In this review, we discuss the cellular and molecular mechanisms that account for the most deleterious effect of hepatic inflammation at the cellular level, that is, the initiation of a massive cell death response among hepatocytes.


Assuntos
Morte Celular/fisiologia , Hepatite/patologia , Hepatite/fisiopatologia , Animais , Apoptose , Autofagia , Senescência Celular , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Humanos , Lipídeos/fisiologia , Fígado/patologia , Fígado/fisiopatologia , Modelos Biológicos , Estresse Oxidativo , Transdução de Sinais/fisiologia , Fator de Necrose Tumoral alfa/fisiologia
19.
Bioorg Med Chem ; 21(17): 5004-11, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23886811

RESUMO

The N-terminal sequence of the Smac/DIABLO protein is known to be involved in binding to the BIR3 domain of the anti-apoptotic proteins IAPs, antagonizing their action. Short peptides and peptide mimetics based on the first 4-residues of Smac/DIABLO have been demonstrated to re-sensitize resistant cancer cells, over-expressing IAPs, to apoptosis. Based on the well-defined structural basis for this interaction, a small focused library of C-terminal capped Smac/DIABLO-derived peptides was designed in silico using docking to the XIAP BIR3 domain. The top-ranked computational hits were conveniently synthesized employing Solid Phase Synthesis (SPS) on an alkane sulfonamide 'Safety-Catch' resin. This novel approach afforded the rapid synthesis of the target peptide library with high flexibility for the introduction of various C-terminal amide-capping groups. The library members were obtained in high yield (>65%) and purity (>85%), upon nucleophilic release from the activated resin by treatment with various amine nucleophiles. In vitro caspase-9 activity reconstitution assays of the peptides in the presence of the recombinant BIR3-domain of human XIAP (500nM) revealed N-methylalanyl-tertiarybutylglycinyl-4-(R)-phenoxyprolyl-N-biphenylmethyl carboxamide (11a) to be the most potent XIAP BIR3 antagonist of the series synthesized inducing 93% recovery of caspase-9 activity, when used at 1µM concentration. Compound (11a) also demonstrated moderate cytotoxicity against the breast cancer cell lines MDA-MB-231 and MCF-7, compared to the Smac/DIABLO-derived wild-type peptide sequences that were totally inactive in the same cell lines.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/química , Proteínas Mitocondriais/química , Peptídeos/síntese química , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/antagonistas & inibidores , Proteínas Reguladoras de Apoptose , Caspase 9/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Células MCF-7 , Micro-Ondas , Peptídeos/toxicidade , Peptidomiméticos , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Resinas Sintéticas/química , Técnicas de Síntese em Fase Sólida , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo
20.
Int J Med Sci ; 10(10): 1278-85, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23983586

RESUMO

Sugammadex, a γ-cyclodextrin that encapsulates selectively steroidal neuromuscular blocking agents, such as rocuronium or vecuronium, has changed the face of clinical neuromuscular pharmacology. Sugammadex allows a rapid reversal of muscle paralysis. Sugammadex appears to be safe and well tolerated. Its blood-brain barrier penetration is poor (< 3% in rats), and thus no relevant central nervous toxicity is expected. However the blood brain barrier permeability can be altered under different conditions (i.e. neurodegenerative diseases, trauma, ischemia, infections, or immature nervous system). Using MTT, confocal microscopy, caspase-3 activity, cholesterol quantification and Western-blot we determine toxicity of Sugammadex in neurons in primary culture. Here we show that clinically relevant sugammadex concentrations cause apoptotic/necrosis neuron death in primary cultures. Studies on the underlying mechanism revealed that sugammadex-induced activation of mitochondria-dependent apoptosis associates with depletion of neuronal cholesterol levels. Furthermore SUG increase CytC, AIF, Smac/Diablo and CASP-3 protein expression in cells in culture. Potential association of SUG-induced alteration in cholesterol homeostasis with oxidative stress and apoptosis activation occurs. Furthermore, resistance/sensitivity to oxidative stress differs between neuronal cell types.


Assuntos
Neurônios/efeitos dos fármacos , gama-Ciclodextrinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Bloqueio Neuromuscular , Neurônios/citologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Sugammadex
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